1. Field of the Invention
The present invention generally relates to a heat exchanger for releasing heat from the inside of a casing to the outside. More particularly, a heat exchanger suitably applicable for a cabinet having an information processing electronic device unit such as a communication apparatus that generates large amounts of heat.
2. Description of the Related Art
In recent years, there has been, for example, an urgent demand for installing next-generation mobile base stations. Along with the growing installment of the next-generation mobile base stations, the demand for outdoor type base station installations has been increasing both domestically and internationally. Such mobile base station installations have an information processing electronic device unit (such as a high performance communication apparatus) installed inside a cabinet. Since the cabinet is disposed outdoors, it is preferable that the cabinet be in a hermetically sealed state.
Since a large amount of heat is generated from the communication apparatus and the like, such heat is to be released to the external. Accordingly, it is preferable to provide a cabinet with a heat exchanger having high thermal efficiency and excellent water-resistance for preventing water from entering in situations such as rain.
FIG. 1 is a diagram showing an example of a conventional cabinet 100 installed with a communication apparatus or the like. The cabinet 100, being installed with a communication apparatus or the like (not shown), generates a large amount of heat. Therefore, the cabinet 100 is provided with a heat exchanger 110 disposed at a portion of a front side door.
The heat exchanger 110 includes, for example, a fan 111 for drawing in external air FA, a heat exchange part 120, and a fan 112 for sending internal high temperature air IHA heated by the communication apparatus to the heat exchange part 120.
The external air FA is turned into a high temperature exhaust air HA by absorbing heat by contacting a heat pipe 121 and a fin 122 in the heat exchange part 120, and is exhausted from the cabinet 100. Meanwhile, the internal high temperature air IHA is turned into an internal low temperature air ICA by having its heat absorbed by contacting the heat pipe 121 and the fin 122, and is re-used for cooling the communication apparatus. Accordingly, the heat exchanger 110 prevents the temperature inside the cabinet 100 from becoming excessively high.
Since the cabinet 100 is disposed outdoors, the cabinet 100 is exposed to wind and rain. Malfunctions in the communication apparatus are caused, particularly, when rain (water) enters the cabinet 100. Therefore, the heat exchange part 120 is provided with a water-resistant partition plate 125 disposed substantially at its center, and is also applied with a sealing process at its surrounding such as applying caulking to joint areas where water is likely to enter.
Meanwhile, in recent years and continuing, the floor area for installing (establishing) the above-described cabinet 100 is becoming smaller, and a demand for installing a high density communication apparatus or the like into the size-reduced cabinet 100 is increasing. Under these circumstances, a heat exchanger with greater thermal efficiency is desired since obtaining more space for installing the heat exchanger is difficult.
However, since the above-described conventional heat exchanger 110 provides low heat exchange effectiveness since the heat exchanger 110 employs a long wave-shaped heat pipe 121 for allowing a cooling medium to flow therethrough. Although it is possible to improve heat exchange performance by increasing the number of heat exchangers, such increase not only causes difficulty in obtaining installment space, but also increases cost, and reduces transportability due to increase of weight.
Furthermore, since the conventional heat exchanger 110 is structured having numerous fins 122 attached to the long heat pipe 121, applying a water-protectant such as the sealing process is difficult and costly. Furthermore, it is difficult in inspecting whether there are any defective (missed) areas in the sealing process. In addition, even if a defective area is found, repairing (reinforcing) the defective area is difficult.
Other than the above-described heat exchanger 110, there is another type of heat exchanger having a heat exchange part with plural planar heating units and heat absorbing units alternately attached to each other. However, this type of heat exchanger requires more manufacture cost since all of its joint portions between each of the units are to be sealed with caulking or the like.